2 * Copyright (c) 2008 open80211s Ltd.
3 * Author: Luis Carlos Cobo <luisca@cozybit.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 #include <linux/kernel.h>
10 #include <linux/random.h>
11 #include "ieee80211_i.h"
15 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
16 #define mpl_dbg(fmt, args...) printk(KERN_DEBUG fmt, ##args)
18 #define mpl_dbg(fmt, args...) do { (void)(0); } while (0)
21 #define PLINK_GET_FRAME_SUBTYPE(p) (p)
22 #define PLINK_GET_LLID(p) (p + 1)
23 #define PLINK_GET_PLID(p) (p + 3)
25 #define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
26 jiffies + HZ * t / 1000))
28 /* Peer link cancel reasons, all subject to ANA approval */
29 #define MESH_LINK_CANCELLED 2
30 #define MESH_MAX_NEIGHBORS 3
31 #define MESH_CAPABILITY_POLICY_VIOLATION 4
32 #define MESH_CLOSE_RCVD 5
33 #define MESH_MAX_RETRIES 6
34 #define MESH_CONFIRM_TIMEOUT 7
35 #define MESH_SECURITY_ROLE_NEGOTIATION_DIFFERS 8
36 #define MESH_SECURITY_AUTHENTICATION_IMPOSSIBLE 9
37 #define MESH_SECURITY_FAILED_VERIFICATION 10
39 #define dot11MeshMaxRetries(s) (s->u.mesh.mshcfg.dot11MeshMaxRetries)
40 #define dot11MeshRetryTimeout(s) (s->u.mesh.mshcfg.dot11MeshRetryTimeout)
41 #define dot11MeshConfirmTimeout(s) (s->u.mesh.mshcfg.dot11MeshConfirmTimeout)
42 #define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
43 #define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
45 enum plink_frame_type {
64 void mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
66 atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
67 mesh_accept_plinks_update(sdata);
71 void mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
73 atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
74 mesh_accept_plinks_update(sdata);
78 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
80 * @sta: mes peer link to restart
82 * Locking: this function must be called holding sta->lock
84 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
86 sta->plink_state = PLINK_LISTEN;
87 sta->llid = sta->plid = sta->reason = 0;
88 sta->plink_retries = 0;
92 * NOTE: This is just an alias for sta_info_alloc(), see notes
93 * on it in the lifecycle management section!
95 static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
96 u8 *hw_addr, u32 rates)
98 struct ieee80211_local *local = sdata->local;
101 if (local->num_sta >= MESH_MAX_PLINKS)
104 sta = sta_info_alloc(sdata, hw_addr, GFP_ATOMIC);
108 sta->flags = WLAN_STA_AUTHORIZED;
109 sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
110 rate_control_rate_init(sta);
116 * mesh_plink_deactivate - deactivate mesh peer link
118 * @sta: mesh peer link to deactivate
120 * All mesh paths with this peer as next hop will be flushed
122 * Locking: the caller must hold sta->lock
124 static void __mesh_plink_deactivate(struct sta_info *sta)
126 struct ieee80211_sub_if_data *sdata = sta->sdata;
128 if (sta->plink_state == PLINK_ESTAB)
129 mesh_plink_dec_estab_count(sdata);
130 sta->plink_state = PLINK_BLOCKED;
131 mesh_path_flush_by_nexthop(sta);
135 * __mesh_plink_deactivate - deactivate mesh peer link
137 * @sta: mesh peer link to deactivate
139 * All mesh paths with this peer as next hop will be flushed
141 void mesh_plink_deactivate(struct sta_info *sta)
143 spin_lock_bh(&sta->lock);
144 __mesh_plink_deactivate(sta);
145 spin_unlock_bh(&sta->lock);
148 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
149 enum plink_frame_type action, u8 *da, __le16 llid, __le16 plid,
151 struct ieee80211_local *local = sdata->local;
152 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
153 struct ieee80211_mgmt *mgmt;
154 bool include_plid = false;
160 skb_reserve(skb, local->hw.extra_tx_headroom);
161 /* 25 is the size of the common mgmt part (24) plus the size of the
162 * common action part (1)
164 mgmt = (struct ieee80211_mgmt *)
165 skb_put(skb, 25 + sizeof(mgmt->u.action.u.plink_action));
166 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.plink_action));
167 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
168 IEEE80211_STYPE_ACTION);
169 memcpy(mgmt->da, da, ETH_ALEN);
170 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
171 /* BSSID is left zeroed, wildcard value */
172 mgmt->u.action.category = PLINK_CATEGORY;
173 mgmt->u.action.u.plink_action.action_code = action;
175 if (action == PLINK_CLOSE)
176 mgmt->u.action.u.plink_action.aux = reason;
178 mgmt->u.action.u.plink_action.aux = cpu_to_le16(0x0);
179 if (action == PLINK_CONFIRM) {
180 pos = skb_put(skb, 4);
181 /* two-byte status code followed by two-byte AID */
184 mesh_mgmt_ies_add(skb, sdata);
187 /* Add Peer Link Management element */
207 pos = skb_put(skb, 2 + ie_len);
208 *pos++ = WLAN_EID_PEER_LINK;
211 memcpy(pos, &llid, 2);
214 memcpy(pos, &plid, 2);
216 if (action == PLINK_CLOSE) {
218 memcpy(pos, &reason, 2);
221 ieee80211_tx_skb(sdata, skb, 1);
225 void mesh_neighbour_update(u8 *hw_addr, u32 rates, struct ieee80211_sub_if_data *sdata,
226 bool peer_accepting_plinks)
228 struct ieee80211_local *local = sdata->local;
229 struct sta_info *sta;
233 sta = sta_info_get(local, hw_addr);
235 sta = mesh_plink_alloc(sdata, hw_addr, rates);
240 if (sta_info_insert(sta)) {
246 sta->last_rx = jiffies;
247 sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
248 if (peer_accepting_plinks && sta->plink_state == PLINK_LISTEN &&
249 sdata->u.mesh.accepting_plinks &&
250 sdata->u.mesh.mshcfg.auto_open_plinks)
251 mesh_plink_open(sta);
256 static void mesh_plink_timer(unsigned long data)
258 struct sta_info *sta;
259 __le16 llid, plid, reason;
260 struct ieee80211_sub_if_data *sdata;
263 * This STA is valid because sta_info_destroy() will
264 * del_timer_sync() this timer after having made sure
265 * it cannot be readded (by deleting the plink.)
267 sta = (struct sta_info *) data;
269 if (sta->sdata->local->quiescing) {
270 sta->plink_timer_was_running = true;
274 spin_lock_bh(&sta->lock);
275 if (sta->ignore_plink_timer) {
276 sta->ignore_plink_timer = false;
277 spin_unlock_bh(&sta->lock);
280 mpl_dbg("Mesh plink timer for %pM fired on state %d\n",
281 sta->sta.addr, sta->plink_state);
287 switch (sta->plink_state) {
291 if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
293 mpl_dbg("Mesh plink for %pM (retry, timeout): %d %d\n",
294 sta->sta.addr, sta->plink_retries,
296 get_random_bytes(&rand, sizeof(u32));
297 sta->plink_timeout = sta->plink_timeout +
298 rand % sta->plink_timeout;
299 ++sta->plink_retries;
300 mod_plink_timer(sta, sta->plink_timeout);
301 spin_unlock_bh(&sta->lock);
302 mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
306 reason = cpu_to_le16(MESH_MAX_RETRIES);
307 /* fall through on else */
311 reason = cpu_to_le16(MESH_CONFIRM_TIMEOUT);
312 sta->plink_state = PLINK_HOLDING;
313 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
314 spin_unlock_bh(&sta->lock);
315 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid, plid,
320 del_timer(&sta->plink_timer);
321 mesh_plink_fsm_restart(sta);
322 spin_unlock_bh(&sta->lock);
325 spin_unlock_bh(&sta->lock);
331 void mesh_plink_quiesce(struct sta_info *sta)
333 if (del_timer_sync(&sta->plink_timer))
334 sta->plink_timer_was_running = true;
337 void mesh_plink_restart(struct sta_info *sta)
339 if (sta->plink_timer_was_running) {
340 add_timer(&sta->plink_timer);
341 sta->plink_timer_was_running = false;
346 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
348 sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
349 sta->plink_timer.data = (unsigned long) sta;
350 sta->plink_timer.function = mesh_plink_timer;
351 sta->plink_timeout = timeout;
352 add_timer(&sta->plink_timer);
355 int mesh_plink_open(struct sta_info *sta)
358 struct ieee80211_sub_if_data *sdata = sta->sdata;
360 spin_lock_bh(&sta->lock);
361 get_random_bytes(&llid, 2);
363 if (sta->plink_state != PLINK_LISTEN) {
364 spin_unlock_bh(&sta->lock);
367 sta->plink_state = PLINK_OPN_SNT;
368 mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
369 spin_unlock_bh(&sta->lock);
370 mpl_dbg("Mesh plink: starting establishment with %pM\n",
373 return mesh_plink_frame_tx(sdata, PLINK_OPEN,
374 sta->sta.addr, llid, 0, 0);
377 void mesh_plink_block(struct sta_info *sta)
379 spin_lock_bh(&sta->lock);
380 __mesh_plink_deactivate(sta);
381 sta->plink_state = PLINK_BLOCKED;
382 spin_unlock_bh(&sta->lock);
386 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
387 size_t len, struct ieee80211_rx_status *rx_status)
389 struct ieee80211_local *local = sdata->local;
390 struct ieee802_11_elems elems;
391 struct sta_info *sta;
392 enum plink_event event;
393 enum plink_frame_type ftype;
397 __le16 plid, llid, reason;
399 /* need action_code, aux */
400 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
403 if (is_multicast_ether_addr(mgmt->da)) {
404 mpl_dbg("Mesh plink: ignore frame from multicast address");
408 baseaddr = mgmt->u.action.u.plink_action.variable;
409 baselen = (u8 *) mgmt->u.action.u.plink_action.variable - (u8 *) mgmt;
410 if (mgmt->u.action.u.plink_action.action_code == PLINK_CONFIRM) {
414 ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
415 if (!elems.peer_link) {
416 mpl_dbg("Mesh plink: missing necessary peer link ie\n");
420 ftype = *((u8 *)PLINK_GET_FRAME_SUBTYPE(elems.peer_link));
421 ie_len = elems.peer_link_len;
422 if ((ftype == PLINK_OPEN && ie_len != 3) ||
423 (ftype == PLINK_CONFIRM && ie_len != 5) ||
424 (ftype == PLINK_CLOSE && ie_len != 5 && ie_len != 7)) {
425 mpl_dbg("Mesh plink: incorrect plink ie length\n");
429 if (ftype != PLINK_CLOSE && (!elems.mesh_id || !elems.mesh_config)) {
430 mpl_dbg("Mesh plink: missing necessary ie\n");
433 /* Note the lines below are correct, the llid in the frame is the plid
434 * from the point of view of this host.
436 memcpy(&plid, PLINK_GET_LLID(elems.peer_link), 2);
437 if (ftype == PLINK_CONFIRM || (ftype == PLINK_CLOSE && ie_len == 7))
438 memcpy(&llid, PLINK_GET_PLID(elems.peer_link), 2);
442 sta = sta_info_get(local, mgmt->sa);
443 if (!sta && ftype != PLINK_OPEN) {
444 mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
449 if (sta && sta->plink_state == PLINK_BLOCKED) {
454 /* Now we will figure out the appropriate event... */
455 event = PLINK_UNDEFINED;
456 if (ftype != PLINK_CLOSE && (!mesh_matches_local(&elems, sdata))) {
468 spin_lock_bh(&sta->lock);
470 /* ftype == PLINK_OPEN */
472 if (!mesh_plink_free_count(sdata)) {
473 mpl_dbg("Mesh plink error: no more free plinks\n");
478 rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
479 sta = mesh_plink_alloc(sdata, mgmt->sa, rates);
481 mpl_dbg("Mesh plink error: plink table full\n");
485 if (sta_info_insert(sta)) {
490 spin_lock_bh(&sta->lock);
492 spin_lock_bh(&sta->lock);
495 if (!mesh_plink_free_count(sdata) ||
496 (sta->plid && sta->plid != plid))
502 if (!mesh_plink_free_count(sdata) ||
503 (sta->llid != llid || sta->plid != plid))
509 if (sta->plink_state == PLINK_ESTAB)
510 /* Do not check for llid or plid. This does not
511 * follow the standard but since multiple plinks
512 * per sta are not supported, it is necessary in
513 * order to avoid a livelock when MP A sees an
514 * establish peer link to MP B but MP B does not
515 * see it. This can be caused by a timeout in
516 * B's peer link establishment or B beign
520 else if (sta->plid != plid)
522 else if (ie_len == 7 && sta->llid != llid)
528 mpl_dbg("Mesh plink: unknown frame subtype\n");
529 spin_unlock_bh(&sta->lock);
535 mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %d %d %d %d\n",
536 mgmt->sa, sta->plink_state,
537 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
540 switch (sta->plink_state) {
541 /* spin_unlock as soon as state is updated at each case */
545 mesh_plink_fsm_restart(sta);
546 spin_unlock_bh(&sta->lock);
549 sta->plink_state = PLINK_OPN_RCVD;
551 get_random_bytes(&llid, 2);
553 mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
554 spin_unlock_bh(&sta->lock);
555 mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
557 mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr,
561 spin_unlock_bh(&sta->lock);
570 reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
573 reason = cpu_to_le16(MESH_CLOSE_RCVD);
574 sta->reason = reason;
575 sta->plink_state = PLINK_HOLDING;
576 if (!mod_plink_timer(sta,
577 dot11MeshHoldingTimeout(sdata)))
578 sta->ignore_plink_timer = true;
581 spin_unlock_bh(&sta->lock);
582 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
586 /* retry timer is left untouched */
587 sta->plink_state = PLINK_OPN_RCVD;
590 spin_unlock_bh(&sta->lock);
591 mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
595 sta->plink_state = PLINK_CNF_RCVD;
596 if (!mod_plink_timer(sta,
597 dot11MeshConfirmTimeout(sdata)))
598 sta->ignore_plink_timer = true;
600 spin_unlock_bh(&sta->lock);
603 spin_unlock_bh(&sta->lock);
612 reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
615 reason = cpu_to_le16(MESH_CLOSE_RCVD);
616 sta->reason = reason;
617 sta->plink_state = PLINK_HOLDING;
618 if (!mod_plink_timer(sta,
619 dot11MeshHoldingTimeout(sdata)))
620 sta->ignore_plink_timer = true;
623 spin_unlock_bh(&sta->lock);
624 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
629 spin_unlock_bh(&sta->lock);
630 mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
634 del_timer(&sta->plink_timer);
635 sta->plink_state = PLINK_ESTAB;
636 mesh_plink_inc_estab_count(sdata);
637 spin_unlock_bh(&sta->lock);
638 mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
642 spin_unlock_bh(&sta->lock);
651 reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
654 reason = cpu_to_le16(MESH_CLOSE_RCVD);
655 sta->reason = reason;
656 sta->plink_state = PLINK_HOLDING;
657 if (!mod_plink_timer(sta,
658 dot11MeshHoldingTimeout(sdata)))
659 sta->ignore_plink_timer = true;
662 spin_unlock_bh(&sta->lock);
663 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
667 del_timer(&sta->plink_timer);
668 sta->plink_state = PLINK_ESTAB;
669 mesh_plink_inc_estab_count(sdata);
670 spin_unlock_bh(&sta->lock);
671 mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
673 mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
677 spin_unlock_bh(&sta->lock);
685 reason = cpu_to_le16(MESH_CLOSE_RCVD);
686 sta->reason = reason;
687 __mesh_plink_deactivate(sta);
688 sta->plink_state = PLINK_HOLDING;
690 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
691 spin_unlock_bh(&sta->lock);
692 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
697 spin_unlock_bh(&sta->lock);
698 mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
702 spin_unlock_bh(&sta->lock);
709 if (del_timer(&sta->plink_timer))
710 sta->ignore_plink_timer = 1;
711 mesh_plink_fsm_restart(sta);
712 spin_unlock_bh(&sta->lock);
719 reason = sta->reason;
720 spin_unlock_bh(&sta->lock);
721 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr,
725 spin_unlock_bh(&sta->lock);
729 /* should not get here, PLINK_BLOCKED is dealt with at the
730 * beggining of the function
732 spin_unlock_bh(&sta->lock);